resource identifiers

[Tony Linde]

Hi Ray,

>    A resource identified by only an 
>    <AuthorityID> and a <ResourceKey> is guaranteed to resolve to a 
>    description stored in a registry.  However, those that include a 
>    <RecordKey> are not.

If you mean that resources with a RecordKey are not stored in the registry
then that's okay. In which case, RecordKey should not be part of the
ResourceID. Maybe you need to wrap Resource ID in another structure, eg:

<RaysBitsID>
  <ResourceID>
    <AuthorityID>www.ncsa.uiuc.edu</AuthorityID>
    <ResourceKey>ADIL/SIA/targeted</ResourceKey>
  </ResourceID>
  <RecordKey>95.DR.01.01.fits:wibble</RecordKey>
</RaysBitsID>

That way, what you did in the rest of RaysBitsID would not matter. If this
was namespaced along with RecordKey then any software which understood the
namespace could handle your structure.

Cheers,
Tony. 


> -----Original Message-----
> From: Ray Plante [mailto:rplante at poplar.ncsa.uiuc.edu] 
> Sent: 27 May 2003 19:35
> To: registry at ivoa.net
> Subject: Re: resource identifiers
> 
> 
> > >   <ResourceID>
> > >     <AuthorityID>www.ncsa.uiuc.edu</AuthorityID>
> > >     
> <ResourceKey>ADIL/SIA/targeted:95.DR.01.01.fits:wibble</ResourceKey>
> > >   </ResourceID>
> > > 
> > > This also solves Roy's OAI problem. The worst string 
> you'll get is:
> > >   
> ivo://www.ncsa.uiuc.edu/ADIL/SIA/targeted:95.DR.01.01.fits:wibble
> 
> I applaud this move to get back to basics.  I would like to suggest 3 
> refinements.  
> 
> 1. Bring back the <RecordKey> as an optional component of the ID.
> 
>    The main reason for this has to do with using the ID to retrieve a 
>    description from the registry.  A resource identified by only an 
>    <AuthorityID> and a <ResourceKey> is guaranteed to resolve to a 
>    description stored in a registry.  However, those that include a 
>    <RecordKey> are not.  Nevertheless, if one has ResourceID that has 
>    RecordKey component, one can still learn something about it by 
>    retrieving the description of the resource it is a part 
> of.  This would 
>    be easier if the record component were separately tagged, 
> rather than 
>    parsing the ResourceKey (e.g. chopping at the first : ) 
> which has to be 
>    done outside of a standard XML parser.
> 
>    Thus,
> 
>    <ResourceID>
>      <AuthorityID>www.ncsa.uiuc.edu</AuthorityID>
>      <ResourceKey>ADIL/SIA/targeted</ResourceKey>
>      <RecordKey>95.DR.01.01.fits:wibble</RecordKey>
>    </ResourceID>
> 
>    (look familiar?  :-)
> 
>    I would add that contents of the RecordKey is entirely up to the 
>    resource owner (apart from what from any character restrictions we 
>    place; see below).
> 
> 2. In the URI form, make # the delimiter between the ResourceKey and 
>    the RecordKey.  
> 
>    This is more in the spirit of the #'s use in URL's in that 
> it points to 
>    a component of a resource.  And because of this connection 
> to URLs, it 
>    is less likely to be used as a non-special character 
> within each of the 
>    components.  (Another way to put this: people will more 
> likely want to 
>    use colon as a regular character, particularly in the RecordKey).
> 
>    (Thanks, Roy)
> 
> 3. We should plan to spell out which are characters are legal 
> and which 
>    are not for each component.  The restrictions should be 
> more stringent 
>    on the AuthorityID and the ResourceKey due to their role 
> in Registry 
>    interfaces.  
> 
> Is this okay?
> 
> cheers,
> Ray
> 
> 
>